1. Field of the Invention
This invention relates to article conveyors and, more particularly, to a conveyor with structure for selectively diverting articles out of a main conveying stream.
2. Background Art
Diverters for articles on conveying structures are well known. It is common to provide a principal conveyor, which may employ an endless belt or driven rollers, to advance articles along a principal conveying path and one or more secondary conveyors, which branch off from the principal conveyor path. Through sometimes relatively sophisticated control systems, articles are selectively diverted out of the main conveying path to the secondary conveyors, which deliver the sorted articles to a desired location.
Heretofore, the article diverting structure has taken a number of different forms. One exemplary system utilizes pushers mounted on article carrying tubes for sliding movement lengthwise of the tubes. The tubes move in an endless path tranverse to their length. The pushers have depending guide elements which extend between the tubes to cooperate with a track system that controls lateral pusher movement as the conveyor operates. This pusher system has proven very successful in operation.
Another type of diverter system employs a plurality of rollers which are elevated during operation to engage desired articles and advance them out of the main conveying stream. The problem with this type of system is that it is quite complicated and consequently expensive from a manufacturing standpoint Further, as systems become more complicated, they are inherently more prone to failure.
This latter system requires at least two separate, interacting systems--one to convey in the principal conveying direction and at least one to divert Intricate control systems are required to time the elevation and operation of the divert structure.
Another problem with the latter system is that if it is desired to divert articles selectively off of either side of a main conveyor over the same conveyor length, more than one divert system is required. That is because each divert system is capable of only one conveying direction. The designer is then faced with the complicated task of fitting three independently operable conveying mechanisms in the same area, where space is at a premium.
Further, the divert mechanism(s) must also be geared differently than the main conveying structure, by a potentially complicated mechanism, so that the articles are rapidly diverted out of the main conveying stream and do not interfere with upstream articles.